Jamieson, Fausset and Brown on Ephesians 3:20

20. unto him--contrasted with ourselves and our needs. Translate, "that is able above all things (what is above all things) to do exceeding abundantly above what we ask or (even) think": thought takes a wider range than prayers. The word, above, occurs thrice as often in Paul's writings, as in all the rest of the New Testament, showing the warm exuberance of Paul's spirit.

according to the power--the indwelling Spirit (Ro 8:26). He appeals to their and his experience. 21. Translate, "Unto Him be the glory (that is, the whole glory of the gracious dispensation of salvation just spoken of) in the Church (as the theater for the manifestation of the glory, Ep 3:10) in Christ Jesus (as in Him all the glory centers, Zec 6:13) to all the generations of eternal ages," literally, "of the age of the ages." Eternity is conceived as consisting of "ages" (these again consisting of "generations") endlessly succeeding one another.